KIT mutations and CD117 overexpression are markers of better progression-free survival in vulvar melanomas.

BACKGROUND: Few studies have addressed prognostic markers and none has correlated molecular status and prognosis in vulvar melanomas. OBJECTIVES: To evaluate the clinicopathological features of 95 cases of vulvar melanoma. METHODS: p53, CD117, Ki-67, neurofibromin, brafv600e and nrasq61r immunostains, and molecular analyses by either targeted next-generation or direct sequencing, were performed on available archival materials. RESULTS: Molecular testing detected mutations in KIT (44%), BRAF (25%), NF1 (22%), TP53 (17%), NRAS (9%) and TERT promoter (9%). Co-mutation of KIT and NF1 and of KIT and NRAS were identified in two and one cases, respectively. KIT mutations were significantly associated with better progression-free survival in univariate analyses. In multivariate analyses CD117 expression was significantly associated with better progression-free survival. Tumour thickness was significantly associated with worse progression-free and overall survival, and perineural invasion significantly correlated with reduced melanoma-specific survival and reduced overall survival. Cases were from multiple centres and only a subset of samples was available for molecular testing. CONCLUSIONS: KIT mutations and CD117 overexpression are markers of better progression-free survival. In addition to its prognostic value, molecular testing may identify cases that might respond to targeted agents or immunotherapeutic approaches.

Defining the histopathological changes induced by nonablative radiofrequency treatment of faecal incontinence--a blinded assessment in an animal model.

AIM: Nonablative radiofrequency (RF) sphincter remodelling has been used to treat gastro-oesophageal reflux disease (GERD) and faecal incontinence (FI). Its mechanism of action is unclear. We aimed to investigate the histomorphological and pathophysiological changes to the internal and external anal sphincter (IAS and EAS) following RF remodelling. METHOD: An experimental FI model was created in 12 female pigs: eight underwent RF 6 weeks following induction of FI (FI+RF) and four were untreated (UFI). Four animals served as controls (CG). Two blinded pathologists examined all haematoxylin and eosin and trichrome stained slides. RESULTS: Compared with the UFI group, histological examination of the IAS in the FI+RF group demonstrated an increased smooth muscle (SM)/connective tissue ratio (77.2 vs 68.1%, P < 0.05) and increased collagen I compared with collagen III content (67.2 vs 54.9%, P < 0.001). The RF+FI group exhibited greater SM bundle thickness compared with the UFI group (SM width 486.93 vs 338.59 µm, P < 0.01; height 4384.4 vs 3321.0 µm, P < 0.05). The EAS of the FI+RF animals showed a significantly higher type I/II fibre ratio (33.5 vs 25.2%, P = 0.023) and fibre type I diameter (67.2 vs 59.7 µm, P < 0.001) compared with the UFI group. Post-RF manometry showed higher basal (18.8 vs 0 mmHg, P < 0.001) and squeeze (76.8 vs 12.4 mmHg, P < 0.05) anal pressures. After RF treatment, the number of interstitial cells of Cajal was significantly reduced compared with the UFI and CG groups [0.9 (FI+RF) vs 6.7 (UFI) vs 0.7 (CG) per mm(2) , P < 0.001]. CONCLUSION: In an animal model nonablative RF appeared to induce morphological changes in the IAS and EAS leading to an anatomical state reminiscent of normal sphincter structure.

Selected immunohistochemical features of conventional renal cell carcinomas coexpressing P53 and MDM2.

Renal clear cell carcinoma (CCRCC) is an aggressive tumor for which new prognostic factors are needed. It has been suggested that CCRCCs co-expressing P53 and MDM2 could represent a special subgroup; therefore the aim of this study was to explore their immunohistochemical features. The material studied consisted of 470 cases of CCRCC. Immunohistochemistry for MDM2, P53, Ki-67, VEGF-A, VEGF-C, VEGF-D, GLUT1, CA9, and CK 7 was performed on tissue microarrays and assessed semi-quantitatively. On average, 6.6% or 5.3% of cases were P53+/MDM2+, depending on the P53 antibody used. The mean percentage of Ki-67 positive cells was 0.6% and p53-positive MDM2-positive cases showed significantly higher expression of Ki-67. The other immunohistochemical parameters studied did not differ between p53-positive MDM2-positive cases and the rest of the subtypes studied. Expression of almost all immunohistochemical markers differed with respect to pT stage; only for CA9 was the difference not significant. Furthermore, almost all immunohistochemical markers studied differed with respect to differences in grade; only for GLUT1 was the difference not significant. Our results suggest that with the exception of Ki-67, there are no significant associations between analyzed markers and the double P53+/MDM2+ phenotype.

Radiotherapy for carcinoma of the vagina. Immunocytochemical and cytofluorometric analysis of prognostic factors.

BACKGROUND AND PURPOSE: The aim of this study was to assess the potential prognostic factors in patients with primary invasive vaginal carcinoma (PIVC) treated with radical irradiation. PATIENTS AND METHODS: The analysis was performed on 77 patients with PIVC treated between 1985 and 2005 in the Maria Sklodowska-Curie Memorial Institute of Oncology, Cancer Center in Krakow. A total of 36 patients (46.8 %) survived 5 years with no evidence of disease (NED). The following groups of factors were assessed for potential prognostic value: population-based (age), clinical (Karnofsky Performance Score [KPS], hemoglobin level, primary location of the vaginal lesion, macroscopic type, length of the involved vaginal wall, FIGO stage), microscopic (microscopic type, grade, mitotic index, presence of atypical mitoses, lymphatic vessels invasion, lymphocytes/plasmocytes infiltration, focal necrosis, VAIN-3), immunohistochemical (protein p53 expression, MIB-1 index), cytofluorometric (ploidity, index DI, S-phase fraction, proliferation index SG2M) factors. RESULTS: Significantly better 5-year NED was observed in patients: < 60 years, KPS ≥ 80, FIGO stage I and II, grade G1-2, MIB-1 index < 70, S-phase fraction < 10, and proliferation index < 25. Independent factors for better prognosis in the multivariate Cox analysis were age < 60 years, FIGO stage I or II, and MIB-1 index < 70. CONCLUSION: Independent prognostic factors in the radically irradiated PIVC patients were as follows: age, FIGO stage, MIB-1 index.

Prognostic value of KIT/PDGFRA mutations in gastrointestinal stromal tumours (GIST): Polish Clinical GIST Registry experience.

BACKGROUND: Majority of gastrointestinal stromal tumours (GISTs) are characterised by KIT-immunopositivity and the presence of KIT/platelet-derived growth factor receptor alpha (PDGFRA) activating mutations. PATIENTS AND METHODS: Spectrum and frequency of KIT and PDGFRA mutations were investigated in 427 GISTs. Univariate and multivariate analysis of relapse-free survival (RFS) was conducted in relation to tumours' clinicopathologic features and genotype. RESULTS: Mutations were found in 351 (82.2%) cases, including 296 (69.3%) KIT and 55 (12.9%) PDGFRA isoforms. Univariate analysis revealed higher 5-year RFS rate in women (37.9%; P = 0.028) and in patients with gastric tumours (46.3%; P < 0.001). In addition a better 5-year RFS correlated with smaller tumour size ≤ 5 cm (62.7%; P < 0.001), tumours with mitotic index ≤ 5/50 high-power fields (60%; P < 0.001), and characterised by (very) low/moderate risk (70.2%; P = 0.006). Patients with GISTs bearing deletions encompassing KIT codons 557/558 had worse 5-year RFS rate (23.8%) than those with any other KIT exon 11 mutations (41.8%; P < 0.001) or deletions not involving codons 557/558 (33.3%; P = 0.007). Better 5-year RFS characterised patients with KIT exon 11 point mutations (50.7%) or duplications (40%). By multivariate analysis, tumours with PDGFRA mutations and KIT exon 11 point mutations/other than 557/558 deletions had lower risk of progression than with KIT exon 11 557/558 deletions (both Ps = 0.001). CONCLUSIONS: KIT/PDGFRA mutational status has prognostic significance for patients' outcome and may help in management of patients with GISTs.

Progesterone but not estradiol 17beta potentiates local GH secretions by hormone-dependent breast cancer explants. An in vitro study.

The aim of this study was to evaluate the effects of treatment of breast cancer explants with tamoxifen (TMX) or RU486 on GH secretory dynamics in the presence of exogenous estrogen (E2), progesterone (P4) or both. Explants obtained during surgery were divided according to their sex steroid hormone receptor status. P4 (10(-7) M) or 17beta-estradiol (10(-5) M) or both were tested in vitro for their ability to induce hGH secretion and cell proliferation. TMX (10(-7) M) was added to E2, RU486 (10(-7) M) to P4, and both were applied to E2 plus P4-supplemented cultures. The stimulatory action of P4 on GH secretion was noted in hormone-dependent (ER+/PR+) but not in hormone-independent explants (ER-/PR-). RU486 did not abolish this effect. The stimulatory action of P4 on GH release was not parallel to the stimulation of cell proliferation. E2 alone was without effect on GH secretion by both types of breast cancer explants. Combined treatment with both steroids stimulated GH secretion and cell proliferation by (ER+/PR+) explants. Both TMX and RU486 reversed this effect on cell proliferation while only RU486 abolished augmentation of GH secretion. In none of the hormone-dependent breast cancers, the combined treatment with E2 and P4 had any effect on GH secretion and cell proliferation. Taken together, these results lead us to the hypothesis that P4 but not E2 potentiates local GH secretion by hormone-dependent breast cancer explants. The fact that RU486 reversed neither GH secretion nor cell proliferation in hormone-dependent explants indicates its non-receptor-mediated mechanism of action.

Prognostic relevance of p53 alterations and Mib-1 proliferation index in subgroups of primary liposarcomas.

For prognostic analyses of p53 alterations (p53 gene mutations + p53 immunopositivity) and Mib-1 proliferation index, we investigated 42 primary malignant lipomatous tumors for which complete clinical data and a long follow-up were available. p53 gene mutations were investigated by PCR-single strand conformation polymorphism-sequencing analysis, and immunohistochemistry was used to determine p53 protein expression and Mib-1 proliferation index. We found a mutation frequency of 14.3%. Nine liposarcomas (21%) were p53 immunopositive, and 11 (26.2%) had at least one p53 alteration. In myxoid liposarcomas, p53 alterations are not relevant to the presence or absence of round cell components. Pleomorphic liposarcomas showed a significantly higher proliferation index and more p53 alterations than myxoid or well-differentiated variants (P<0.001). When the Cox's regression analysis tumors of grade III histology (P = 0.005) was performed, the pleomorphic subtype (P = 0.016) and liposarcomas of retroperitoneal localization (P = 0.015) showed a significantly poorer prognosis. Moreover, we found that p53 alterations and high proliferation index correlated significantly with reduced overall survival. Their prognostic value seemed to be higher in myxoid than in pleomorphic liposarcomas. The metastasis-free survival was reduced in patients who had liposarcomas with p53 alterations (P = 0.171) or elevated proliferation index (P<0.016), reflecting a more aggressive behavior. In conclusion, the determination of p53 alterations and/or Mib-1 proliferation index is useful for assessing the prognosis of patients with liposarcomas and may especially be helpful in dividing different prognostic groups for patients with myxoid variants.

Prognostic significance of telomerase activity in soft tissue sarcomas.

Only few reports on the prognostic significance of telomerase activity in human cancer exist. To find a new prognostic marker in soft tissue tumors, we investigated 60 soft tissue sarcomas of different histology and six benign tumors for telomerase activity. Telomerase activity was measured by using the non-radioactive PCR-based TRAP-assay. PCR products were analyzed on an automated fluorescence sequencer. Tumors of grade-II and grade-III histology showed a significantly poorer prognosis. Both disease-free (p<0.03) and the overall survival (p<0.02) were reduced in the highly malignant sarcoma patients. We found telomerase activity in 38.3% of the cases, there being a correlation with a more aggressive behavior of soft tissue sarcomas. Telomerase activity correlated with the grade of malignancy (p=0.04), but not with sex (p=0.64) or age (p=0. 48) of the patients. The total survival was significantly reduced in patients with telomerase-positive sarcomas (p=0.04). Both of the patients having grade I tumors with telomerase activity died of disease, whereas 10 of 11 patients with telomerase-negative grade I tumors are still alive. Only one of the benign tumors showed telomerase activity. We suggest that telomerase activity is a potential prognostic factor in malignant soft tissue tumors. Despite the histological heterogeneity of soft tissue tumors, single entities should be assessed for telomerase activity.

Gene alterations at the CDKN2A (p16/MTS1) locus in soft tissue tumors.

The CDKN2A gene (p16/MTS1) is a tumor suppressor that is frequently deleted, mutated, or inactivated by transcriptional silencing in certain tumor types and many tumor cell lines. We analyzed CDKN2A gene mutations and the frequency of loss of heterozygosity (LOH) at the CDKN2A locus in 135 soft tissue sarcomas. PCR-SSCP analysis of exons 1 and 2 of CDKN2A gene revealed only one missense mutation in codon 15 in a rhabdomyosarcoma. LOH-analysis was performed with two polymorphic markers in the surrounding regions of the CDKN2A gene (D9S171, D9S162) and the sequence-tagged-site marker c5.1. An allelic loss was found in 7/135 cases (5.1%) and was a characteristic of poorly differentiated sarcomas. We observed a high frequency of microsatellite instability expressed as allelic imbalances (25%). Presumably, alterations of the CDKN2A gene do not contribute to the oncogenesis in the majority of soft tissue tumors.

Nonrandom secondary chromosome-aberrations in synovial sarcomas with t(x-18).

Thirty samples from 19 patients with synovial sarcoma were analyzed cytogenetically after short-term culturing. Thirteen samples were from primary tumors, 11 from local recurrences, and six from distant metastases. All samples showed the characteristic aberration t(X;18)(p11;q11) or variants thereof; 23 samples had additional numerical and/or structural changes. Including the present cases, chromosome aberrations have been reported in 74 synovial sarcomas, 50 of which have had secondary aberrations in addition to t(X;18). No secondary structural aberration was recurrent. The most common numerical changes were +7, +8, +12 (10 cases each), -3, +9, +21 (7 cases each), +2, -14, -17 (6 cases each), +4, -11, +15, and -22 (5 cases each). Unbalanced stuctural aberrations led to loss of 3p and 17p in six cases, each with loss of bands 3p21 and 17p13, respectively, in common. Most monosomies and trisomies seemed to occur at similar frequencies in primary, recurrent, and metastatic tumors. The only exceptions were +2, which was never seen in a primary tumor, and +8, which was never found in any metastatic lesion.

p53 gene mutations and expression of p53 and mdm2 proteins in invasive breast carcinoma. A comparative analysis with clinico-pathological factors.

The aim of the study was to analyze p53 gene mutations and the expression of p53 and mdm2 proteins in 31 randomly selected invasive breast carcinomas. The results were then correlated with tumor grade, stage, estrogen receptor status, nodal status, and DNA ploidy. The expression of the proteins p53 and mdm2 was determined immunohistochemically using formalin-fixed, paraffin-embedded material. Screening for p53 mutation involved analysis of the highly conserved regions of the p53 gene (exons 5-9) by the polymerase chain reaction/ single-strand conformation polymorphism (PCR-SSCP) technique. PCR products with band shifts were directly sequenced. Immunohistochemical staining of p53 was positive in 9 cases (29.0%), only 2 of which showed a p53 gene mutation. These were identified as a C-->G transversion at the second position of codon 278 in exon 8 and an A-->G transition at the second position of codon 205 in exon 6. A third case with a mutation was observed (C-->T transition, position 1 of codon 250 in exon 7) that did not show p53 immunohistochemically. Of the 9 p53-positive tumors, 2 were moderately differentiated (grade II). The remaining tumors were poorly differentiated (7/9). By contrast, p53-negative carcinomas were well differentiated (grade I) in most cases (P = 0.02). DNA cytometry in 8 of the 9 p53-positive carcinomas revealed an aneuploid stem line. The majority of the p53-negative tumors were diploid (P = 0.01). Mdm2 oncoprotein was detected in 10 tumors (32.2%), 4 of which were p53-positive, including the 3 with mutations. The grading of the mdm2-positive tumors was moderate or poor, G1 carcinomas were always noted to be mdm2-negative (P = 0.04). Overexpression of p53 protein is a complex mechanism and does not merely indicate the detection of mutations in the p53 gene. This study has shown that p53 expression correlates with tumor grade and DNA ploidy. Mdm2 expression was also associated with the tumor grade. Immunohistological demonstration of the p53 protein alone is insufficient as a basis for comment on the functional state of the p53 gene and gene product. The interrelation between recognition of the p53 protein and gene mutation needs more careful assessment to define their roles in the control of neoplasia.

p53 gene mutations in soft-tissue sarcomas--correlations with p53 immunohistochemistry and DNA ploidy.

The significance of p53 mutations in a group of 67 soft-tissue tumors was examined using single-strand conformation polymorphism and direct sequencing analysis. Molecular findings were correlated with immunohistochemical detection of the p53 protein and DNA ploidy status. Mutations of the p53 gene were detected in 13 (19.5%) out of 67 cases of soft-tissue tumors. Only three were localized outside the conservative regions of the p53 gene. Six mutations were described for the first time in these tumors. Most of the mutations were point mutations in exons 5-8 and, in one case, a deletion at the 3'-splice site of exon 5 could be demonstrated. There was no significant correlation between the occurrence of p53 mutations and the histological grade, although a high number of mutations were defined in poorly differentiated tumors (grade 3). Molecular finding of a p53 gene mutation and immunohistochemical detection of p53 expression did not correlate, which may be due to the high percentage of nonsense mutations in our study (50%). We confirm that only DNA sequencing allows a unique identification and differentiation of mutations in the p53 gene. Other factors may be responsible for the detection of p53 protein in many cases. Histological grade correlated with aneuploidy. The frequency of mutations observed was in accordance with values quoted in the literature. Generally, p53 mutations and p53 overexpression are more likely to represent a late event in the oncogenesis of soft-tissue tumors.

Expression of multidrug-resistance-associated protein gene in human soft-tissue sarcomas.

We examined the mRNA expression of the multidrug- resistance-associated protein gene (MRP) in soft-tissue sarcomas and compared it with the expression of the multidrug resistance gene (MDR1), using the reverse transcriptase/polymerase chain reaction. We investigate 39 samples from 33 cases of soft-tissue sarcomas (11 liposarcomas, 9 malignant fibrous histiocytomas, 6 leiomyosarcomas, 4 malignant schwannomas, 3 fibrosarcomas, 3 synovial sarcomas, and 3 epithelioid sarcomas) and 7 benign soft-tissue tumors. All samples were obtained prior to chemotherapy. An expression of MRP mRNA was noted in 56% of soft-tissue sarcoma specimens. The co-expression of MRP and MDR1 was recognized in 15 samples (38%) (5/11 liposarcomas, 5/9 malignant fibrous histiocytomas, 3/6 leiomyosarcomas, 2/3 fibrosarcomas) and significantly correlated with histological grade (P=0.0165). A positive and significant correlation was found between MRP and MDR1 expression in soft-tissue sarcomas(P=0.0013). In benign soft-tissue tumors, 1 chemodectoma and 1 neurothekeoma showed low MRP expression; however, no case showed co-expression of MRP and MDR1.

MDM2 amplification and loss of heterozygosity at Rb and p53 genes: no simultaneous alterations in the oncogenesis of liposarcomas.

PURPOSE: The present study aimed to investigate the status of alterations of the MDM2, Rb and p53 genes in a series of 45 liposarcomas. Furthermore, the possible correlation with histological and clinical parameters was studied. METHODS: MDM2 amplification was examined by non-radioactive Southern blot hybridization with a human MDM2 cDNA probe. Mutations in the p53 gene were screened by polymerase chain reaction/single-strand conformation polymorphism analysis and direct sequencing. To study loss of heterozygosity (LOH) at the tumor-suppressor genes Rb and p53, we used four polymorphic intragenic Rb markers (introns 1, 17, 20, and 25) and two p53 markers (intron 1 and exon 4). RESULTS: MDM2 amplification was found in 19 of 45 liposarcomas (42.2%). The frequency of LOH in Rb and p53 was nearly identical (22%). In 4 of 9 tumors (44.4%) with LOH, allelic loss was a concurrent event in both genes. Of 45 liposarcomas, 6 (13.3%) showed p53 mutations. Overall, alterations of the p53/MDM2/Rb pathway occurred in 30 of 45 liposarcomas (66.6%). In contrast to myxoid and pleomorphic variants, well-differentiated liposarcomas were characterized by a high frequency of MDM2 amplification, a lack of LOH of Rb and p53, and p53 mutations. CONCLUSIONS: Obviously MDM2 amplification and LOH at the Rh and p53 genes do not occur simultaneously in the oncogenesis of liposarcomas, as is the case for MDM2 amplification and p53 gene mutations (with one exception). We suggest that well-differentiated, myxoid and pleomorphic liposarcomas are characterized by a different pattern of molecular alterations.

Cytogenetic and immunohistochemical profile of myxoid liposarcoma.

Cytogenetic and immunohistochemical studies were performed in nine myxoid liposarcomas. The tumor karyotype was determined after short-term culture of cells in vitro. Immunohistochemical studies were performed on frozen tissue in five cases and on paraffin-embedded tissue in three cases. Chromosomal analysis demonstrated a balanced translocation t(12;16) (q13;p11) as the sole abnormality in four cases. Two cases showed an association with other abnormalities. Three tumors showed variants of the t(12;16) translocation involving other chromosomes. In all cases studied, the 12q13 breakpoint was involved in rearrangements. In the majority of cases, immunohistochemical studies demonstrated vimentin (9 of 9) and S-100 protein (8 of 9). Strong focal expression of desmin was observed in two tumors. Weak focal expression was observed in three tumors. Two tumors, which were both desmin positive, showed focal expression of MSA and alpha-SMA. Strong expression of CD36 was present in all four cases that were studied for this marker. CD34 was negative in tumor cells, but it highlighted an intricate capillary network in the tumor. Close relationship between the tumor cells and pericapillary pericytes was demonstrated with CD34 and alpha-SMA strains. The authors conclude that myxoid liposarcoma is characterized by a specific chromosomal rearrangement. Its immunohistochemical profile is wider than previously believed, including expression of muscle markers.

No correlation of c-myc overexpression and p53 mutations in liposarcomas.

Although it is well known that oncogenesis is a multistep process involving the activation of normal cellular genes to become oncogenes and/or the inactivation of tumor suppressor genes, this process has seldom been investigated in soft tissue tumours. We screened a group of 36 liposarcomas for genetic abnormalities in the p53 tumour suppressor gene and c-myc oncogene. Altered c-myc gene expression was examined by differential RT-PCR assay. p53 Gene mutations in exons 4-8 were analysed by using PCR-SSCP analysis and direct sequencing. Elevated c-myc expression was found in 6 of 31 liposarcomas (19.4%). p53 Gene mutations were observed in 5 of 36 liposarcomas (13.9%). Both genetic alterations were associated with the histological subtype of liposarcomas. Whereas c-myc gene expression was a characteristic of myxoid/round cell liposarcomas, p53 gene mutations were found more frequently in pleomorphic variants. Liposarcomas of the well-differentiated subtype showed neither p53 gene mutations nor altered c-myc gene expression. Our results indicate that the c-myc oncogene and the p53 tumor suppressor gene do not seem to cooperate in the oncogenesis of liposarcomas.

Reverse transcriptase-polymerase chain reaction amplification of MDR1 gene expression in adult soft tissue sarcomas.

Expression of the multidrug resistance gene MDR1 is reported to be an important determinant of the response to chemotherapy and survival in some cancers. We compared three methods for determining the intrinsic MDR1 expression in soft tissue sarcomas. We studied MDR1 gene expression in 39 samples from 33 cases of soft tissue sarcomas comprising 11 liposarcomas, nine malignant fibrous histiocytomas, six leiomyosarcomas, four malignant schwannomas, three fibrosarcomas, three synovial sarcomas, and three epithelioid sarcomas, and seven cases of benign soft tissue tumors in adult patients. To detect MDR1 mRNA, reverse transcriptase-polymerase chain reaction (RT-PCR) was performed in all samples. Furthermore, RNA dot-blot analysis with digoxigenin-labeled RNA probe and immunohistochemistry with JSB-1 and C-219 antibodies for P-glycoprotein were employed in 34 and 37 samples in soft tissue sarcomas, respectively. We compared these three detection techniques. Of the 39 specimens, 18 (46%) showed MDR1 PCR products. Liposarcomas (six of 11), malignant fibrous histiocytomas (six of nine), leiomyosarcomas (four of six), fibrosarcomas (two of three) revealed high or intermediate MDR1 expression at high frequency. No MDR1 expression was detectable in malignant schwannomas, synovial sarcomas, or epithelioid sarcomas. Of seven benign soft tissue tumors, one ganglioneuroma and one lipomatosis showed low levels of MDR1 expression. By RNA dot-blot analysis, MDR1 transcripts were detectable in 12 of 34 specimens (35%). Four samples were negative by dot blot despite positivity with RT-PCR. Concordance between MDR1 expression by RNA level with RT-PCR and dot blot and at the protein level with immunohistochemistry using C-219 was found in 16 (47%) of the 34 comparable specimens. Eight samples showed positive immunoreactivity for C-219 despite negative results in RT-PCR and dot-blot analysis. The intrinsic MDR1 expression in soft tissue sarcoma seemed to depend on certain tumor types, such as liposarcoma, malignant fibrous histiocytoma, leiomyosarcoma, and fibrosarcoma. For the evaluation of MDR1 expression, RT-PCR is useful because of its relative simplicity and sensitivity. However, the clinical significance of such low levels of MDR1 expression detected only by RT-PCR must be discussed within systematically treated patient groups.

Parachordoma: a rare sarcoma with clonal chromosomal changes.

This is the first report on clonal chromosomal aberrations in a metastatic parachordoma lesion. All neoplastic cells had the karyotype 33-47,X,der(X)t(X;3) (p11;p11),der(3)t(3;6)(p11;q13), del(6)(q13), -9, -13,r(13), +mar. The presence of t(X;3) with a breakpoint at band Xp11 as in synovial sarcoma may suggest a common histological origin of the two tumor types.

A rare chimeric TLS/FUS-CHOP transcript in a patient with multiple liposarcomas: a case report.

Myxoid liposarcomas harbor a unique and specific t(12;16)(q13,p11) chromosomal translocation. The breakpoint has recently been identified, and involvement of the TLS/FUS gene on chromosome 16 and the CHOP gene on chromosome 12 was demonstrated. We report a case of a 45-year-old woman who developed multiple malignant lipomatous tumors of unknown origin and myxoid/round cell histology at different locations. To examine the diagnostic potential of this translocation and to develop a hypothesis on the origin of the tumors, we used cytogenetic and molecular cytogenetic methods (reverse transcription polymerase chain reaction, RT-PCR). We identified a chimeric RNA transcript in the second recurrence in the thigh/groin, as well as in another tumor in the mediastinum, which has an additional sequence of 33 bp, known as fusion transcript type III. Cytogenetic analysis of another tumor in retroperitoneal space revealed a rare type of unbalanced translocation der(16)t(12;16). We hypothesize that these tumors are metastases rather than multicentric tumors. The detection of the chimeric message in the present case is not only useful for differential diagnosis, but also for analyzing the origin of multiple neoplasms.

Abnormal karyotypes in three carcinomas of the gallbladder.

Short-term cultures from three carcinomas of the gallbladder were cytogenetically analyzed. All three had an abnormal karyotype. The modal chromosome number was near- or hypertriploid in two tumors and near diploid in the third. Structural rearrangements of chromosomes 1 and 3, loss of material from the long arm of chromosome 18, and loss of chromosome 21 material were common to all three tumors and would seem to be the best candidates for nonrandom karyotypic changes in carcinomas of the gallbladder.